Improvement in hot-air furnaces



N0.133,096, Patented Nov.19,1872.

UNITED S'rn'rns PATENT @arten VILLIAM H. HARRIS, OF BUFFALO, NEW YORK, ASSIGNOR TO CHARLES VALLETTE KASSON, OF SAME PLACE.

IMPROVEMENT IN HOT-AIR FURNACES.

Specification forming part of Letters Patent No. 133,696, dated Novunber 19, 1872.

To all whom it may concern:

Be it known that I, VVLLLIAM H. HARRIS, of the city of Buffalo, in the county of Erie and State of New York, have invented certain Improve-ments in Hot-Air Furnaces, ot' which the following is a specification:

My improvements relate to ordinary hot-air furnaces provided with air-heating pipes arranged in the combustion-chamber and surrounded by a metallic case or brick-work, from which the hot air is conducted by suitable pipes to the apartments to be heated. Prior to my invention such furnaces have also been constructed with a supplemental radiatingchamber provided with air-pipes and arranged above the combustion-chamber, from which the products of' combustion were conducted through flues arranged on the outside thereof to said supplemental chamber. My invention consists, iirst, in the combination, with the combustionchamber and outer connectingilues, of revertible flue-pipes made pendent from the lower end of said connecting-ihres, by which the products of combustion are made to descend within the combustion-chamber before they enter said connecting-hue; second, in the arrangement of the pendent revertible ilue, with the flue with which it communicates at the joint thereof, in such manner that the end ot' the pendent iiue will project upward into the nue above so as to leave a V- shaped annular space, into which cinders or ashes collect, and thereby form a self-packing joint; third, in the arrangement in the combustion-chamber of the air-heating pipes, with the upper ends secured to the top plate thereof so as to be pendent therefrom, while their loose lower ends fit over a projecting sleeve or collar of the bottom plate, leaving a space between the latter and the end of the pipe, which allows the pipes to freely expand without tend- .ing to force apart the top and bottom plates of the top plate, thereby securing the sides and plate together, at the same time forming a suitable space for receiving aud holding the material for packing the joint.

In the accompanying drawing, consisting of two sheets, Figure I is a sectional elevation on line w w, Fig. II 5 Figs. II, III, and IV are horizontal sections, respectively, on lines a', y y, and z z, Fig. I; Fig. V is a partly-sectional elevation of the upper portion otv the furnace, showing the damper; Fig. VI is a detached sectional view on an enlarged scale ot' one of the revertible pendent rluesand connecting-iiue; Fig. VII is a detached sectional view of the joint of the sides of the combustion-chamber with the top thereof; and Figs. VIII and 4IX are views representing a modified mode of attaching the air pipes and tlues to the top plate of the combustion-chamber.

Like letters designate like parts in each ot' the gures.

A represents the outer case. of the furnace, provided in the bottom, in the usual manner, with apertures a for the admission of the cold air, and in the top with air-escape apertures a', with which the hot-air conduit-pipes connect. B is the ash-pit, and G the {ire-pot, provided with tlie grate c, all of ordinary construction. D represents the combustion-ch amber, composed of the bottom plate d, resting in a groove formed in the top of the dre-pot, a top plate, (l1, both constructed of cast-iron, and a sheet-iron shell, cl2. E is the supplemental radiating-chamber arranged above the combustion-chamber D. It is provided with vertical air-pipes e, ope-n at both ends. fare tlues leading from the combustion-chamber into the space surrounding the air-pipes o. g is the central vertical iiue connecting the combustion and radiating chamber with the exitpipe h, and g1 the damper arranged below the latter in the flue g, and operated by a rod, g2, or in any other suitable manner. 7trepresents the pendent revertible ues arranged below each of the connecting-luesf, and extending to within a short distance from the bottom plate d, so as to leave sufficient space below said flues for the free entrance of the products of combustion. They are secured to the under side of the top plate of the combustion-chamber by means of a bolt or bolts, fi,

passing through an ear or flange cast with the pendent iiue, or in any other suitable manner. lhe upper end of the revertible flue k extends upward to the lue j", whereby an annular space, or V-shaped groove, k, is formed between both, as clearly shown in Fig. VI, which is gradually lled with ashes and cinders, thereby forming a self -packing joint. The iiues f are held in place by a concentric sleeve or collar cast on the upper side of the top plate d', in the usual manner.

W' hen a direct draft is required the damper g1 is opened, which permits the products of combustion to pass from the combustionchamber directly to the exit-pipe h. By closing the damper, as shown in the drawing, the products of combustion are made to descend within the combustion-chamber, in order to enter the revertible iues L', in which they ascend, passing thence through the fluesf, enter the radiating-chamber E, from whence they dive, and pass through the central iiue g into the exit-pipe 7L, as indicated by arrows in Fig. I. The heated gases are in this manner reta-ined longer in their course to theiinal escape-pipe, which permits the greater portion of heat to be absorbed therefrom by the air which enters the pipes c, and that surrounding the radiating-chamber. Zrepresents the air-heating pipes, arranged within the combustion-chamber, and rigidly secured to and suspended from the under side of the top plate thereof. These pipes may be fastened to the top plate in the same manner as the pendentilues k, or as represented in Figs.VIII and IX. A plate, i', may be fitted between two of the pipes so as to overlap the top lian ges thereof, which plate, being bolted to the top plate, will secure two pipes or the sides'of two pipes in place. The pipes l extend to within a very short distance of the bottom plate d, so as to leave sufficient space for expansion between the latter and the end of the pipe, and t snugly over a projecting sleeve or collar, l', formed around the airinlet aperture of the bottom plate. Hitherto these pipes have been arranged in contact with both the top and bottom plates, the pipes resting on the bottom plate while the top plate rested on the upper ends of the pipes. With this arrangement I have found from experience that the greater heat to which tl'iefainpipes are subjected, would cause them to lengthen by expansion more than the sheet-iron case, and thus force open the joints, and cause a leal;- age of the gas. Upon the pipes cooling and contracting a space would be left between the upper ends of the pipe and the top plate, through which the gas would escape into the airpipes. My improved arrangement by which the pipes are suspended, and the joint and the top of the pipes made rigid, I have found, after a thorough test and use for over a year, to be an effectual remedy for these defects. m represents air-conduit pipes, preferably arranged below each of the air-heating pipes I, so as to commuicate therewith, and resting on a horizontal plate, m', surrounding the ashpit B, for the purpose of insuring a supply of cold air to the air-pipes l, to prevent overheating the same. wardly-proj eeting flan ge formed on the outside of the top plate dl of the combustion-chamber, so as to tit over the upper edge of the shell d2 thereof. o is the connecting-ring secured to the outside of the shell d2 below the flan ge u, by riveting or otherwise, and overlapping the latter with its bent upper edge, as clearly shown in Fig. VII. This not only secures the shell and plate together, but also forms a space between the ring o and shell d2, which is filled with a suitable cement or packing material, thereby insuring a gas-tight joint.

Vhat I claim as my invention is- 1. The combination, with the combustionchamber, supplemental radiatin g-chamber and connecting-nues f, of the pendent revertible flues 7a within the chamber D, substantially as hereinbefore set forth.

2. The arrangement of the pendent revertible fines 7c, with the conneeting-tlucsf, so as to leave an annular space, 7c', at their junction, forming a self-packing joint, as hereinbefore set forth.

3. The arrangement in the combustion-chamber of a hot-air furnace, of the air-pipes l, suspended at their upper endsfrom the top plate d, to which they are rigidly secured, while their lower ends lit over upwardly-proj ecting sleeves of the base-plate, between which and the ends of the pipes suflicient space is left for the expansion of the pipes, substantially as hereinbefore set forth.

4. The combination, with the sheet-iron shell d2, of the combustion-chamber and top plate dl thereof, provided with a flange, n, of the connecting-rin g o, secured to the shell d2, and overlapping the outer edge of the plate di, so as to connect both and form a packing space, substantially as hereinbefore set forth.

WM. II. HARRIS. lVitnesses:

JNO. J. BoNNnR, EDWARD WILHELM.

a, Fig. VII, represents a down. 

